Intern night call is a widely used method for providing care to acutely ill patients 24 hours a day in teaching hospitals. Several features of the intern call night have been implicated as potentially harmful to patients; however, alternatives to existing call schedules have been criticized as being expensive, posing similar risks for patients, and providing inadequate postgraduate medical training. As this debate continues and the pressure to reform training rises, it will be necessary to understand how patient outcomes are affected by the circumstances of intern call. The purpose of our research will be to quantify the effects of intern on-call workload, one important aspect of the intern call night experience, on inpatient medical care. Specifically, we will investigate how the number of new hospital admissions, the rate of assignment of new admissions, and existing inpatient responsibilities affect the resource utilization and outcome of care of patents in teaching hospitals. The study will be a retrospective analysis of all patients admitted over eight years to on-call interns on the Internal Medicine service of a city/county teaching hospital in Minnesota. We will use length of stay, total charges, charges per hospital day, and intensive care unit utilization as the dependent variables indicating resource use. In-hospital mortality, early readmission, nursing home placement, and rate of nosocomial infection will be the indicators of patient outcome. For each of these dependent variables we will test the hypothesis that the variable is affected by the workload of the admitting intern. We will also examine the functional form of any relationships identified, and will look for interactions with other characteristics of the patients, the physicians, and the environment in which care is delivered.